Segment Information (Subscription Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total Subscription revenue	$ 767,170	$ 732,901	$ 2,427,044	$ 2,200,741
Subscription [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	262,604	159,873	774,290	457,312
Subscription, SaaS [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	137,831	100,857	391,019	277,512
Subscription, Non-SaaS [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	$ 124,773	$ 59,016	$ 383,271	$ 179,800